This is the most common cause of these error messages. Try this first before trying other solutions below. 

• Confirm the Problem
  • Click Windows Start.
  • Type msinfo32.exe.
  • Click System Information (App)
  • Check if System Information shows “Can’t Collect Information” as shown in the following picture. 
  • If this is confirmed, it indicates an issue with the Windows Management Instrumentation service. Otherwise, skip to the next solution. 

• The Solution
  • Open the Windows Services by typing Services into the Windows Start. 
  • Open this as Administrator or you may not have permissions to stop the service. 
  • Check for the service Windows Management Instrumentation and stop it. 
  • Open Notepad (Start -> Run -> Notepad) or another text editor. 
  • Add the following text (copy/ paste):

@echo on
cd /d c:\temp
if not exist %windir%\system32\wbem goto TryInstall
cd /d %windir%\system32\wbem
net stop winmgmt
winmgmt /kill
if exist Rep_bak rd Rep_bak /s /q
rename Repository Rep_bak
for %%i in (*.dll) do RegSvr32 -s %%i
for %%i in (*.exe) do call :FixSrv %%i
for %%i in (*.mof,*.mfl) do Mofcomp %%i
net start winmgmt
goto End

:FixSrv
if /I (%1) == (wbemcntl.exe) goto SkipSrv
if /I (%1) == (wbemtest.exe) goto SkipSrv
if /I (%1) == (mofcomp.exe) goto SkipSrv
%1 /Regserver
:SkipSrv
goto End
:TryInstall
if not exist wmicore.exe goto End
wmicore /s
net start winmgmt
:End

• • Save the document with the name WBEM_Fix.bat somewhere where you can easily find it. 
  • Right-click on the saved file and choose “Run as Administrator”. You may be prompted for some admin credentials. 
  • A command prompt will appear. Enter the letter “Y” and click enter on your keyboard to start the process. This will take some time to run, but when it finishes, it will close itself. 
  • Once this window closes, try running Revit again.
  • IF YOU PREFER, DOWNLOAD THE FILE FROM HERE INSTEAD. EXTRACT THE FILE AFTER DOWNLOADING TO RUN IT. Download File
  • If this solution does not solve the problem, move to the next one.